The biological research on anti-breast cancer drugs focuses on the activity of estrogen receptors alpha (ER\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\alpha$$\end{document}α), the pharmacokinetic properties and the safety of the compounds, which, however, is an expensive and time-consuming process. Here, ESR1 is linked to breast cancer.